tetano
Editor, Senior Moderator
Front Microbiol
. 2020 Oct 22;11:583588.
doi: 10.3389/fmicb.2020.583588. eCollection 2020.
Truncation or Deglycosylation of the Neuraminidase Stalk Enhances the Pathogenicity of the H5N1 Subtype Avian Influenza Virus in Mallard Ducks
Sujuan Chen[SUP] 1 2 3 4 [/SUP], Keji Quan[SUP] 1 [/SUP], Dandan Wang[SUP] 1 [/SUP], Yinping Du[SUP] 1 2 3 [/SUP], Tao Qin[SUP] 1 2 3 4 [/SUP], Daxin Peng[SUP] 1 2 3 4 [/SUP], Xiufan Liu[SUP] 1 2 3 [/SUP]
Affiliations
Abstract
H5N1 subtype avian influenza virus (AIV) with a deletion of 20 amino acids at residues 49-68 in the stalk region of neuraminidase (NA) became a major epidemic virus. To determine the effect of truncation or deglycosylation of the NA stalk on virulence, we used site-directed mutagenesis to insert 20 amino acids in the short-stalk virus A/mallard/Huadong/S/2005 (SY) to recover the long-stalk virus (rSNA+). A series of short-stalk or deglycosylated-stalk viruses were also constructed basing on the long-stalk virus, and then the characteristics and pathogenicity of the resulting viruses were evaluated. The results showed that most of the short-stalk or deglycosylated-stalk viruses had smaller plaques, and increased thermal and low-pH stability, and a decreased neuraminidase activity when compared with the virus rSNA+. In a mallard ducks challenge study, most of the short-stalk or deglycosylated-stalk viruses showed increased pathological lesions and virus titers in the organ tissues and increased virus shedding in the oropharynx and cloaca when compared with the rSNA+ virus, while most of the short-stalk viruses, especially rSNA-20, showed higher pathogenicity than the deglycosylated-stalk virus. In addition, the short-stalk viruses showed a significantly upregulated expression of the immune-related factors in the lungs of the infected mallard ducks, including IFN-α, Mx1, and IL-8. The results suggested that NA stalk truncation or deglycosylation increases the pathogenicity of H5N1 subtype AIV in mallard ducks, which will provide a pre-warning for prevention and control of H5N1 subtype avian influenza in the waterfowl.
Keywords: H5N1 subtype AIV; glycosylation; mallard duck; neuraminidase; pathogenicity.
. 2020 Oct 22;11:583588.
doi: 10.3389/fmicb.2020.583588. eCollection 2020.
Truncation or Deglycosylation of the Neuraminidase Stalk Enhances the Pathogenicity of the H5N1 Subtype Avian Influenza Virus in Mallard Ducks
Sujuan Chen[SUP] 1 2 3 4 [/SUP], Keji Quan[SUP] 1 [/SUP], Dandan Wang[SUP] 1 [/SUP], Yinping Du[SUP] 1 2 3 [/SUP], Tao Qin[SUP] 1 2 3 4 [/SUP], Daxin Peng[SUP] 1 2 3 4 [/SUP], Xiufan Liu[SUP] 1 2 3 [/SUP]
Affiliations
- PMID: 33193225
- PMCID: PMC7641914
- DOI: 10.3389/fmicb.2020.583588
Abstract
H5N1 subtype avian influenza virus (AIV) with a deletion of 20 amino acids at residues 49-68 in the stalk region of neuraminidase (NA) became a major epidemic virus. To determine the effect of truncation or deglycosylation of the NA stalk on virulence, we used site-directed mutagenesis to insert 20 amino acids in the short-stalk virus A/mallard/Huadong/S/2005 (SY) to recover the long-stalk virus (rSNA+). A series of short-stalk or deglycosylated-stalk viruses were also constructed basing on the long-stalk virus, and then the characteristics and pathogenicity of the resulting viruses were evaluated. The results showed that most of the short-stalk or deglycosylated-stalk viruses had smaller plaques, and increased thermal and low-pH stability, and a decreased neuraminidase activity when compared with the virus rSNA+. In a mallard ducks challenge study, most of the short-stalk or deglycosylated-stalk viruses showed increased pathological lesions and virus titers in the organ tissues and increased virus shedding in the oropharynx and cloaca when compared with the rSNA+ virus, while most of the short-stalk viruses, especially rSNA-20, showed higher pathogenicity than the deglycosylated-stalk virus. In addition, the short-stalk viruses showed a significantly upregulated expression of the immune-related factors in the lungs of the infected mallard ducks, including IFN-α, Mx1, and IL-8. The results suggested that NA stalk truncation or deglycosylation increases the pathogenicity of H5N1 subtype AIV in mallard ducks, which will provide a pre-warning for prevention and control of H5N1 subtype avian influenza in the waterfowl.
Keywords: H5N1 subtype AIV; glycosylation; mallard duck; neuraminidase; pathogenicity.